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Oliver Upton authored
* kvm-arm64/ffa-proxy: : pKVM FF-A Proxy, courtesy Will Deacon and Andrew Walbran : : From the cover letter: : : pKVM's primary goal is to protect guest pages from a compromised host by : enforcing access control restrictions using stage-2 page-tables. Sadly, : this cannot prevent TrustZone from accessing non-secure memory, and a : compromised host could, for example, perform a 'confused deputy' attack : by asking TrustZone to use pages that have been donated to protected : guests. This would effectively allow the host to have TrustZone : exfiltrate guest secrets on its behalf, hence breaking the isolation : that pKVM intends to provide. : : This series addresses this problem by providing pKVM with the ability to : monitor SMCs following the Arm FF-A protocol. FF-A provides (among other : things) a set of memory management APIs allowing the Normal World to : share, donate or lend pages with Secure. By monitoring these SMCs, pKVM : can ensure that the pages that are shared, lent or donated to Secure by : the host kernel are only pages that it owns. KVM: arm64: pkvm: Add support for fragmented FF-A descriptors KVM: arm64: Handle FFA_FEATURES call from the host KVM: arm64: Handle FFA_MEM_LEND calls from the host KVM: arm64: Handle FFA_MEM_RECLAIM calls from the host KVM: arm64: Handle FFA_MEM_SHARE calls from the host KVM: arm64: Add FF-A helpers to share/unshare memory with secure world KVM: arm64: Handle FFA_RXTX_MAP and FFA_RXTX_UNMAP calls from the host KVM: arm64: Allocate pages for hypervisor FF-A mailboxes KVM: arm64: Probe FF-A version and host/hyp partition ID during init KVM: arm64: Block unsafe FF-A calls from the host Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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